Electron spin resonance and polarographic studies of the anion radicals of heterocyclic amine N-oxide was written by Kubota, Tanekazu;Nishikida, Koichi;Miyazaki, Hiroshi;Iwatani, Kouji;Oishi, Yoshiko. And the article was included in Journal of the American Chemical Society in 1968.Category: pyridine-derivatives This article mentions the following:
Polarograms of 30 heterocyclic amine N-oxide were recorded in HCONMe2 at ∼25°. E.S.R. spectra of radical anions formed during controlled-potential electrolysis at the potential corresponding to the first reduction wave were observed for 16 of the oxide. The hydrogen (aH) and nitrogen (aN) hyperfine coupling constants were determined by the method of spectral simulation. With 4-cyano- and 4-nitropyridine N-oxide anion radicals, D substitution was used to confirm the anal. Hueckel M.O. calculations with the McLachlan modification, where the necessary parameters were chosen to give agreement with the αH’s of pyrazine N,N’-dioxide, 4-cyanopyridine N-oxide, and pyrazine mono-N-oxide, yielded the following linear relations between calculated spin density, ρ, and exptl. coupling constant for the compounds studied: αH = -25.7σc and aN = 42.6ρN – 6.7(ρc + ρc’) – 19.0ρo. Also, using fewer parameters, αN was satisfactorily expressed by aN = 41.9ρN – 2.1. In addition, E.S.R. spectra of the anion radicals of pyridine N-oxide and its 2,6-dideuterio derivative were observed during electrolysis in liquid NH3. The comparison of the αH’s and aN so observed with the calculated values using the equations above was in good agreement. Also the polarographic data were analyzed in terms of radical stability and were related to the E.S.R. results as follows. The peak height of the a.c. polarogram and the half-wave potential (E1/2) of the first reduction wave are approx. linearly related to the radical stability. Moreover, the E1/2 is in linear relation with the lowest vacant M.O. energy (εLV) and also with the Hammett σ value of a series of substituted pyridine N-oxide. Thus, E1/2 = 2.75εLV – 0.77 and – E1/2 = 1.08σ – 2.19. The results are compared with those of related compounds reported in the literature. In the experiment, the researchers used many compounds, for example, 3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8Category: pyridine-derivatives).
3,5-Dimethylpyridine 1-oxide (cas: 3718-65-8) belongs to pyridine derivatives. In contrast to benzene, Pyridine’s electron density is not evenly distributed over the ring, reflecting the negative inductive effect of the nitrogen atom. Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. Pyridine-based materials are valued for their optical and physical properties as well as their medical potential. Category: pyridine-derivatives